Harvesting

Section IV: Harvesting

The information below, is an excerpt from the "Recommendations for Coffee Berry Borer Integrated Pest Management in Hawai‘i 2020" document. The complete article can be downloaded here.

Start the season with as low an infestation as is feasible and then to use “efficient harvesting” and spraying. An efficient harvest includes harvesting to avoid over- ripe cherries and raisins on the tree, removing all ripe/ over-ripe/raisin coffee at each harvest, and minimizing dropped coffee. The latter is essential to ensure that CBB carryover to the next season is as low as possible.

A. Pre-harvest Strip Pick

The strip-pick at the end of the previous season will invariably miss some berries, and with stray blossoms and small flowerings before the main flowering event, any residual mature coffee berries on the farm will provide refuge for CBB between the seasons.

An early season strip-pick, timed somewhere between the main bloom and when the main crop is still very immature, is an opportunity to remove infested berries before CBB are able to emerge and infest the new crop. This should occur before the first harvest of the main crop.

Although the first round of coffee harvested will typically yield very little marketable coffee compared to main round-harvested coffee, growers should avoid leaving this first-round cherry and raisin on the trees. Similar to the berries that were carried over between seasons, this crop will serve as a reservoir from which CBB will emerge and infest subsequent rounds.

The first round of harvest often has a high level of CBB and may be treated as a sanitation strip-pick if all mature green, color-break, ripe, over-ripe, and raisin cherry are picked.
Since CBB will sit in the A/B position until the coffee berry is mature enough, having only im- mature berries on the tree also might help the efficiency of sprays by leaving CBB in a vulner- able position for a longer time.
Process and/or destroy all fruit from this first- round harvest. An option is to float the harvest by dumping it into a container of water and removing the raisins and badly damaged berries which rise to the surface.

B. Main Harvest

1. Picker training

Coffee cherry and raisin left in the trees and on the ground could harbor CBB [16] and become reservoirs for the remainder of the current season and the next season. Coffee farmers should supervise pickers and impress upon them the importance of efficient harvesting and removing all ripe and dropped fruit. Farmers may combine performance goals with economic incentives such as not hiring the picker again, paying for greens and raisin, and hourly pay.

Pick any over-ripe and raisin cherry when harvesting.
Pick up dropped cherry from the ground, if possible.
Avoid discarding green berries, over-ripe cherry, and raisin from the picking basket onto the ground.
- Leave in the picking basket or discard in a separate container.
- Small amounts may be discarded in a container with soapy water.
Harvests can be pre-processed by adding a sorting stage, such as floating, to remove reject coffee before delivery to the mill.

2. Harvest interval or frequency

Interrupt the CBB breeding cycle with frequent and complete harvests. Coffee farmers should avoid harvest intervals of more than a month to prevent the escape of CBB from berries as well as to keep infested over-ripe cherry from falling to the ground.

A harvest interval of 2–3 weeks is ideal for CBB control.
- A longer harvest interval will increase the number of remaining raisin and over-ripe cherry.
- Harvest color-break to red, raisin, and over-ripe cherry.
Avoid an interval length that would allow over-ripe cherry to fall to the ground.

3. Harvest bags

When infested cherry are placed in burlap bags, CBB will escape and can reinfest developing fruit in the field. Lining the inside of the burlap bag with a plastic bag is effective at minimizing the number of escapes.

Tie bags shut at harvest to avoid the escape of CBB and re-infestation of the field.
Avoid keeping bags in the field in the sun all day.
- Take bags to the wet mill as soon as possible.
- Coffee left in bags in the sun will begin to rot.
Avoid transporting cherry in bags through clean areas, and do not move cherry in bags to clean areas within the farm, especially if bags are not closed or lined with a plastic bag.

C. Post-harvest

1. Contain and kill CBB in wet mill

Processors can take the following precautions to avoid infesting surrounding coffee.

Screen the entire wet mill or portions of it, such as the flotation and fermentation tanks, to keep CBB from escaping.
Maintain CBB traps in the wet mill.
- Traps seem to be more effective in enclosed areas.
Cover skin, pulp, and mucilage piles with a tarp and secure the edges.
Disinfest empty burlap bags:
- Heat to 122˚F (50˚C) for at least 25 minutes [8], or
- Boil in water for 5 minutes, or
- Soak overnight in soapy water.

2. Transportation of CBB to other fields

To prevent CBB from escaping, hitchhiking, and being released back to farms on trucks, tightly tie shut plastic-lined burlap bags, and clean coffee cherry-delivery trucks and equipment with soapy water following deliveries and before re-entering the farm.

If the farm is not yet infested, provide picking supplies and do not allow pickers and guests to enter the farm with vehicles, shoes, hats, clothing, and other materials that are potentially infested with CBB from other farms. Do not accept cherry and unroasted coffee from other farmers without a disinfestation protocol prior to delivery.

3. Contain and kill CBB at the dry mill

Enclose the drying deck with plastic or screen.
Dry parchment to at most 10.7% moisture level.
- CBB may still be alive, but they do not infest adjacent uninfested green beans [7].
- Rapid mechanical drying may kill CBB.
- Low humidity (50–60%) helps mitigate CBB by encouraging beetles to evacuate the bean.
GrainPro® bags are good for storage, but CBB can chew through the bags.

Tips and recommendations to help you control CBB during your main harvest

Learn how to estimate your % bean damage (CBB defects) in harvested cherry

Further reading:
[7] Gautz, L.D. 2012. Personal communications. 15 2012 May.
[8] Gautz, L.D., and A.J. Bowles. 2012. Determining effects of time, temperature, and humidity on mortality of coffee berry borer (Hypothenemus hampei). Presented at the 24th International Conference on Coffee Science, San Jose, Costa Rica. 11-16 November 2012.
[16] Johnson, M.A., S. Fortna, R.G. Hollingsworth, and N.C. Manoukis. 2019. Postharvest population reservoirs of coffee berry borer (Coleoptera: Curculionidae) on Hawai’i Island. Journal of Economic Entomology. 112(6): 2833-2841. https://doi.org/10.1093/jee/toz219.

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